The man was shot dead after he appeared to be accelerating his car into police officers at an intersection.

A man in Philadelphia has been shot dead after he tried to mow down police officers with his car.

According to police reports, the unidentified suspect was stopped by police at an intersection. He reversed and slammed into a police vehicle and appeared to be preparing to accelerate into officers manning a blockade.

Five officers fired at the man, killing him instantly. Defending their actions, Upper Darby Police Superintendent Michael Chitwood said the officers had feared for their lives and "did what they had to do".

He added that he did not know if the man had a weapon. The suspect had reportedly made threats to kill police officers and FBI agents in a video posted online earlier.

The shooting comes a week after a man, who made similar threats on social media, shot two New York Police Department officers dead in their patrol car and then killed himself in a subway station.

Officers Rafael Ramos and Wenjian Liu were ambushed on a Brooklyn street where they were shot multiple times by Ismaaiyl Brinsley.

Brinsley had earlier stated in online posts that he was motivated by the high-profile killings of unarmed black men by white police officers, namely Michael Brown in Ferguson, Missouri, and Eric Garner in New York.

Several death threats were made against police in the US in the days after the killings of the two NYPD officers.